This invention relates generally to the use of glycolic compositions as airborne disinfectants and to the electrostatic delivery of such compositions to the environment.
It has been long known in the art that certain glycol compounds and compositions containing them can provide an air sanitation effect when appropriately dispersed. Although various regulatory guidelines are applicable, disinfecting compositions containing about 5 weight percent or more of the active glycol constituent are effective when dispensed into the environment at an adequate rate.
It has been known to use indirect heating of a wick as a method of dispensing various biocidic materials. In particular, U.S. Pat. No. 5,591,395 describes such methods and apparatus for disinfecting air with glycolic compositions. Therein, the method is described as immersing a portion of a porous wick in a liquid composition, then indirectly heating the top of the wick to generate airborne particles of the active disinfecting agent. Certain glycolic compounds readily provide particles, forming an aerosol suspension, at temperatures which can be safely employed in conjunction with apparatus described. The active particles are believed to be contact disinfectants, with respect to airborne bacteria and/or other discrete particulates present.
However, indirect heating methods are not without deficiencies. Various disinfectant compositions may present an undue flammability risk. The heat generated invariably raises ambient temperatures, a side effect counterproductive for an air-conditioned or otherwise temperature controlled environment. The resulting particle size may be difficult to control or ineffectual with respect to optimum sanitization.
The search for an efficient, effective delivery system has been an ongoing concern in the art. One approach, which has been used with some success, is as described in U.S. Pat. Nos. 5,196,171 and 5,382,410: the controlled generation of vapors and/or aerosols from liquids is accomplished by applying a regulated DC voltage to a wick-like, porous emitter or generator assembly supplied with a dispensable liquid. An electrostatic charge is applied to the liquid by means of an electrode positioned in contact with the wick assembly connected to a power supply. The wick assembly includes, preferably, a porous, capillary material through which the liquid passes to exposed, vapor-emitting fiber tips. Specific liquid formulations are left unaddressed by the '171 and '410 patents. Suitable liquids are described only generally as including those which may include disinfectant and/or fragrance agents which impart their respective properties upon delivery.